Ribbon feed mechanism



May 31, 1938. B.- BERIA 2,118,963

RIBBON FEED MECHANISM Filed April 7, 1957' s Sheets-Sheet 1 Fig. 1

y 1,193s. B. BERIA 2,118,963

RIBBON FEED MECHANISM Filed April 7, 1937 3 Sheets-Sheet 2 35 fi N 24 25May 31,1938. B. BERIA 2,118,963

RIBBON FEED MECHANISM Fild April 7-, 1937 s Sheets-Sheet a Patented May31, 1938 I UNITED STATES RIBBON FEED MECHANISM Biagio Beria, Turin,Italy Application April '7, 1937, Serial No. 135,576 In Italy April 10,1936 7 Claims.

This invention relates to a mechanism by means of which the inkingribbon of printing devices is advanced by a step-by-step movement andthe direction of feed is reversed before the ribbon is all unwound froma spool.

It is an object of this invention to insure a reliable advance andreversal of the ribbon by making the engagement of the driving pawl withthe ratchet wheel positive.

A further object of this invention is to maintain said reliability inworking for a long time without the necessity of overhauls orreplacement of parts, by eliminating striking of the driving pawl on theratchet wheel during the return stroke of the pawl. These featuresrender the mechanism according to this invention more particularlysuitable for use in connection with cash registers and other registeringmachines.

Further objects of the invention will appear from the detaileddescription of the drawings in which a preferred form of the object ofthe invention is illustrated. In this preferred form each of the twospools for the inking ribbon is solidly connected with a ratchet wheeland the two pawls for actuating said wheels are articulated to a supportwhich is oscillated reciprocately by the printing mechanism. An abutmentwhich is displaced by the inking ribbonas unwinding is near completion,is struck by one of the two pawls at the end of the idle or returnstroke whereby the pawl is brought into engagement. At the end of theforward stroke the pawls strike against a further abutment which bringsthem out of engagement.

Figure 1 is a front view of the ribbon feed mechanism;

Figure 2 is a section on the line II-II of Fig. 1.

Figure 3 is in its left half a section on the line III-III, in its righthalf a section on the line III---III of Figure 2.

Figure 4 is a partial section on the line IV-'-IV of Figure 2.

Figure 5 is a more diagrammatical view showing the mechanism drivingmeans and the path of the ribbon on a smaller scale.

The base plate I has fixedly attached thereto a vertical wall 2 formedwith a central opening 2 and side flanges 3, 3 (Figures 2 and 3). Apivot 4, 4' is mounted on each of the flanges 3, 3 and is fixedlyconnected with one of the spools 5, 5 for the inking ribbon 6. Theribbon 6 travels from the spool 5 over the spool I as far as the edge 9,inclined through 45, of the plate I, on which it is deflected at rightangles. Thence the ribbon travels over an inclined edge on the otherside of the plate I, is bent at right angles again and passing over theroller 'I' reaches the spool 5'. In the printing zone which is situatedbetween the inclined edges 9, the'plate I is formed with a recess I0(Fig. 3). Two levers I2 and I2 are pivoted by means of the pivots 8 and8' on the front wall 2 and their ends control the inking ribbon 6 whichis fitted with two eyelets, hooks or the like I3, said eyelets being asmall distance apart from the respective ribbon ends. Shortly beforeunwinding of the ribbon from one spool is completed, the eyelet I3 atthis end abuts the lever I2 or I2, respectively, and oscillates itagainst the action of the spring II or II, respectively.

A slidable plate I4 is guided by means of two slits I5, I5 on the pivotsI6, I6 screwed in the upper portion of the wall 2. The plate I4 isformed above with a flange I1 and below with two cams I8, I8 enteringthe opening 2 in the wall 2. The plate I4 is either in the positiondisplaced towards the right, as shown in Figure 1, or in the positiondisplaced towards the left, according as to whether the inking ribbon isbeing wound on the spool 5, in which case the plate is in its right-handposition or on the spool 5 in which case the plate is in its left-handposition. The plate displacement produces in the manner hereinafterdescribed the reversal of the ribbon-feed and is obtained by means ofthe following mechanism. The plate I 4 is provided with a centralabutment I9 which is situated in the path of two arms 20, 20' pivotedafter the manner of scissors on the bush 2| mounted in the lower portionof the wall 2. The arms are provided with teeth 20*, 20* and extensions20 and 20" between which the actuating spring 43 is stretched. The arms20, 20 are normally situated in the position shown in Figure 1 for thearm 20', in which the tooth 20 bears against the action of spring 43 onthe step 42 formed on the above mentioned lever I2. As shown also byFigure 1, as the eyelet I3 of the inking ribbon strikes against thelever I2, the latter is rocked clockwise and the step 42 on the lever I2is released from the tooth 20, so that the lever 20 under the action ofspring 43 performs an oscillation towards the right displacing the plateI4 by means of the abutment I9. The displacement towards the left isperformed as the other eyelet I3 strikes against the lever I2, therebyreleasing the tooth 20" and rocking the arm 20' towards the left. Asshall be hereinafter described, after each reversal, the arm 20 or 20'having moved the plate is returned to its normal position, in which itstooth 20 or 20" bears on the respective step 42, by the member 44 whichmoves downwardly pushing apart the inner sides of the flanges 20 and 20on the arms 20, 20' against the tension of spring 43, till the step 42under the action of spring II or II is returned underneath itsrespective tooth 20 or 20*.

The ribbon feed mechanism is driven by the cam 45 (Fig. 5) performing oneach printing operation a turn which is transformed into a reciprocatingoscillation of the lever 46 pivoted at 41 and under the action of thereturn spring 48. An arm on the lever 46 acts by means of a pin and slotguide on the lever 49 keyed on the shaft 23, having further keyedthereto the arm 24; consequently, the latter is oscillated reciprocallyon each operation. The arm 24 acts by means of a pin (25) and slot guideon the beam 26 keyed on the pivot 21 extending between the abovementioned pivots 4 and 4' for the spools 5, 5'. The pivot 21 is arrangedin the support 22 having its upper portion U-shaped and secured by meansof the screw 22 to the wall 2, and carries two arms 28, 28'.

The beam 26 and two arms 28, 28 therefore perform on each printingoperation a forward oscillation indicated in Fig. 2 by the arrow A and areturn oscillation indicated by the arrow B. A pawl 29, 29' isarticulated to each arm 28, 28' by means of a pivot 32, 32',respectively. A ratchet wheel 3| is actuated by the pawl 29 and aratchet wheel 3| is actuated by the pawl 29', the former wheel beingfixedly connected with the pivot 4 for the spool 5, while the latter isfixedly connected with the pivot 4 for the spool 5 for the inking ribbon6.

According as to whether the pawl 29 or 29 is in engagement with thewheel 3| or 3| during oscillation in the direction A, the spool 5 orspool 5' is positively operated and the inking ribbon winds up thereon.This engagement of either pawl 29 or 29' is produced by the flange IT onthe plate l4, whilst at the end of each forward or operative oscillationof the arms 28, 28', both pawls 29, 29' are positively disengaged bytheir extensions 35, striking against a cross bar 38 mounted on theflanges 3 and 3. At the end of the return oscillation of the arms (idlestroke in the direction B) the extensions 35, 35' enter slots withinclined bottom 2 opening into the opening 2 in the wall 2, andaccording to the position of the plate l4 the extension 35 on the pawl29 or the extension 35' on the pawl 29' strikes the flanges I! on theplate, whereby the respective pawLengages the ratchet wheel 3|, 3|,respectively. Supposing the last displacement of the plate H has beenproduced by the eyelet l3 provided on the ribbon 6 near the spool 5 bystriking against the lever l2, the flange II has come into the path ofthe extension 35 on the pawl 29 and at the end of each returnoscillation (direction B) the pawl 29 is engaged so that on the nextforward oscillation the spool 5 is driven and the ribbon 6 is unwoundfrom the reel 5'. In the position shown in Fig. 1 the eyelet |3 comingfrom the spool 5' strikes against the lever |2. The flange I1 is removedfrom the path of the extension 35 and enters the path of the extension35' on the pawl 29'. The ratchet wheel 3| and spool 5' are thereuponpositively rotated whilst the pawl 29 is left all the time disengagedfrom its ratchet wheel 3|. A small cylinder 44 is arranged on the rearend of the beam 26 and oscillates on each operation in the space betweenthe two arms 20, 2|! returning after displacement of the plate H therespective arm 20 or 20 to its normal position.

To keep the pawls 29, 29 in a determined position with respect to thearms 28, 28' till they strike against the cross bar 38 or flange H, theend of each pawl is provided with a leaf spring 4| acting on a ballarranged in a hole in the pawl (Fig. 4). Depending upon the engaged ordisengaged position of the respective pawl, the ball 40 enters one orthe other of two recesses 39 in the oscillating arms 28, 28', keepingthe pawl in the desired position with respect to the arm 23 or 28, tillit is disengaged by striking against the rod 38 or engaged by thestriking against the flange Opposite each ratchet wheel 3|, 3| a stoppawl 30 is articulated by means of the pin 33 to the fixed support 22and is drawn to its engaged position by the spring 31. To release thespool 5 or 5' from which the inking ribbon 6 unwinds, the stop pawlacting on the ratchet wheel 3|, 3| of said spool should remaindisengaged. This is effected in accordance with the displacements of theplate I 4 by the cams I8 and I8. Said cams act upon the extension 34 onthe stop pawls 30.

In the position shown in Figures 1 and 2, in which the pawl 29, 35 isinoperative, the extension 34 on the stop pawl 30 is pushed by the caml8, so that the pawl remains out of engagement of the respective stopwheel 3|. As soon as the plate I4 is arranged to actuate the pawl 29,35, the stop pawl 30 of the respective ratchet wheel 3| is released andis left in engagement with said wheel 3| by virtue of the tension of thespring 31.

While I have shown but one embodiment of my invention, it is obviousthat it may be embodied in other forms covered and defined by theappended claims.

What I claim is:

1. A ribbon feed mechanism having two spools for the ends of the ribbon,comprising for each spool, in combination, a ratchet wheel coupled forrotation with the spool, a pawl for driving said ratchet wheel, asupport for said driving pawl, means for imparting a reciprocatorymovement to said support, a stop for said driving pawl to bring it outof engagement from the ratchet wheel at the end of its operative stroke.a second stop for the driving pawl to bring it into engagement with theratchet wheel at the end of its return stroke, and ribbon controlledmeans for bringing said second stop into and out of operative position.

2. A mechanism according to claim 1, in which the two spools, ratchetwheels and pawl supports are pivoted side by side about a common axis.

3. A ribbon feed mechanism having two spools for the ends of the ribbon,comprising for each spool, in combination, a ratchet wheel coupled forrotation with the spool. a pawl for driving said ratchet wheel, asupport for said driving pawl, means for imparting a reciprocatorymovement to said support, a stop for said driving pawl to bring it outof engagement from the ratchet wheel at the end of its operative stroke,a second stop for the driving pawl to bring it into engagement with theratchet wheel at the end of its return stroke, a spring latch betweensaid driving pawl and its support for retaining the driving pawl in itsengaged and disengaged position, and ribbon controlled means forbringing said second stop into and cut of its operative position.

4. A ribbon feed mechanism having two spools for the ends of the ribbon,a slide and ribbon controlled means for displacing said slide,comprising for each spool, in combination, a ratchet wheel coupled forrotation with the spool, a pawl for driving said ratchet wheel, asupport for said driving pawl, means for imparting a reciprocatorymovement to said support, a stop for said driving pawl to bring it outof engagement from the ratchet wheel at the end of its operative stroke,a second stop for the driving pawl to bring it into engagement with theratchet wheel at the end of its return stroke, said second stop beingmounted on said slide in such manner as to come into and out of itsoperative position by the efiect of the displacements of the slide, astop pawl for said ratchet wheel, a spring for bringing said stop pawlinto engagement with the ratchet wheel, and a cam on said slide forbringing said stop pawl out oi. engagement from the ratchet wheel.

5. A ribbon feed mechanism having two spools for the ends of the ribbon,a slide and ribbon controlled means for displacing said slide,comprising for each spool, in combination, a ratchet wheel coupled forrotation with the spool, a pawl for driving said ratchet wheel, asupport for said driving pawl, means for imparting a reciprocatorymovement to said support, a stop for said driving pawl to bring it outof engagement from the ratchet wheel at the end of its operative stroke,a second stop for the driving pawl to bring it into engagement with theratchet wheel at the end of its return stroke, said second stop beingmounted on said slide in such manner as to come into and out of itsoperative position by the eifect of the displacements of the slide, aspring latch between said driving pawl and its support for retaining thedriving pawl in engaged and disengaged position, a stop pawl for .saidratchet wheel, a spring for bringing said stop pawl into engagement withthe ratchet wheel, and a cam on said slide for bringing said stop pawlout of engagement from the ratchet wheel.

6. A ribbon feed mechanism having two spools for the ends of the ribbonand a displaceable slide, comprising for each spool, in combination, aratchet wheel coupled for rotation with the spool, a pawl for drivingsaid ratchet wheel, a support for said driving pawl, means for impartinga reciprocatory movement to said support, a stop for said driving pawlto bring it out of engagement from the ratchet wheel at the end of itsoperative stroke, a second stop for the driving pawl to bring it intoengagement with the ratchet wheel at the end of its return stroke, saidsecond stop being mounted on said slide in such manner as to come intoand out of operative position by the eilect of the displacements of theslide, a spring actuated lever for displacing said slide, a ribboncontrolled latch for retaining said lever in inoperative position, and arestoring member for said lever coupledwith said pawl supports.

7. A ribbon feed mechanism having two spools for the ends of the ribbonand a displaceable slide, comprising for each spool, in combination, aratchet wheel coupled for rotation with the spool, a pawl for drivingsaid ratchet wheel, a support for said driving pawl, means for impartinga reciprocatory movement to said support, a stop for said driving pawlto bring it out of engagement from the ratchet wheel at the end of itsoperative stroke, a second stop for the driving pawl to bring it intoengagement with the ratchet wheel at the end of its return stroke, saidsecond stop being mounted on said slide in such manner as to come intoand out of operative position by the eflfect of the displacements of theslide, a spring latch between said driving pawl and its support forretaining the driving pawl in engaged and disengaged position, a stoppawl for said ratchet wheel, a spring for bringing said stop pawl intoengagement with the ratchet wheel, a cam on said slide for bringing saidstop pawl out of engagement from the ratchet wheel, a springactuatedlever for displacing said slide, a ribbon controlled latch for retainingsaid lever in inoperative position, and a restoring member for saidlever coupled with said pawl supports.

BIAGIO BERIA.

